Some reciprocating internal combustion engines have a main and pilot fuel injection performed by a same fuel injector. The fuel injectors may be fed by a common rail, where for example each injector includes a pressure intensification mechanism to perform the main injection at an increased pressure and performs a pilot injection using the common rail pressure. Accordingly, a relatively complex configuration may be required for each injector.
Some internal combustion engines, including some rotary engines, include a pilot subchamber for pilot ignition. However, known arrangements are not optimized, in terms of combustion arrangements and characteristics, and thus room for improvement exists.